146 



NATURE 



[Dec. 14, 1876 



indeed essential, to have at hand separate parts of skeletons, or 

 individual bones, which may be kept in boxes, drawers, cases, or 

 in any way found to be most convenient. Entire skeletons wirh 

 the bones separated occupy very little space in boxes, and the 

 most characteristic parts may be selected and mounted in the 

 way I shall presently indicate. 



Everyone in charge of a biological museum, however small, 

 should be familiar with the mode of preparing skeletons. I can 

 only indicate the outlines of the process, for in this, as in every 

 other part of the work of making anatomical preparations, a few 

 practical lessons from a person already an adept, and a little 

 exiDerience and observation will do more than any description. 

 When the principles are known, the details can be carried 

 out with such modifications and improvements for each indi- 

 vidual case, as the skill and ingenuity ot the operator can suggest. 

 With regard to museum specimens generally, the question is fre- 

 quently asked how such or such a preparation is made, and an 

 answer is expected in a few words, which will enable the questioner 

 to do the same himself. This is much as if a novice who had 

 never handled a brush were to ask an artist how he had painted 

 his picture and expect that a few simple directions would put him 

 on a level with the master. Preparation-making is an art which 

 can only be acquired by labour and perseverance, superadded to 

 some natural qualifications not possessed in an equal degree 

 by all. 



To return to the bones, as in many respects the simplest kind 

 of preparations. There is a popular notion that skeletons are made 

 by putting animals into ant-hills. So I have been told over and 

 over again ever since I was a child. I must, however, say that I 

 havenever actually seen, or evenheardof a skeleton really made in 

 this way, though ants, doubtless, especially in hot countries, v.'ill 

 make short work of the flesh of an animal's body, leaving at 

 least all the larger bones untouched. But we must adopt some 

 safer and more universally applicable method of proceeding. 

 Another common idea is that some "chemical" substance is 

 necessary to steep them in for dissolving the soft parts, and I am 

 often asked " What acid do you use for this purpose ? " when a 

 little reflection would have shown that the bones would be the 

 first parts to disappear under the influence of such a menstruum. 

 No — water — pure water, is the only thing required in preparing 

 bones and skeletons in the great majority of cases, and in the 

 proper use of the water the art of "macerating," as it is called, 

 chiefly consists. 



This process is nothing more or less than placing bones in water 

 and leaving them undisturbed until putrefaction of all the flesh 

 and blood remaining on and around them and within the hollows 

 and small cavities of their interior, takes place, and these soft 

 parts entirely lose their form and structure and become converted 

 into liquids and gases mingled with the water or escaped from 

 its surface ; so that when the bones are removed and well 

 washed, nothing remains but the comparatively indestructible 

 true osseous tissue, which, when dried, is hard, clean, and with- 

 out smell. 



Maceration consists, then, essentially in the destruction of the 

 soft tissues by putrefaction, and certain circumstances are essential 

 or favourable to the success of the process. In the first place, 

 the water should not be too abundant in proportion to the 

 amount of animal matter to be destroyed. Then it should never 

 be changed or disturbed until tlie process is completed. The 

 surface should be exposed to the air, and the loss from evapora- 

 tion supplied from time to time. The temperature should be 

 uniform and elevated. Cold checks the process ; freezing 

 arrests it altogether. If the heat is too great tie bones are often 

 greasy and discoloured, as when they are prepared by boiling. 

 It is to the fact that the process varies in rapidity according to so 

 many circumstances that the chief practical difficulty, which is to 

 know when it is completed, is due. If the bones are taken out 

 too soon, unless they are returned immediately to jjthe same 

 water, a check takes place in their preparation. To estimate 

 the necessary time is a matter acquired only by practice and 

 knowledge of the surrounding circumstances. Much will de- 

 pend upon the size of the bones, small bones macerating much 

 more rapidly than large ones ; also upon their condition, if 

 fresh, they macerate far more quickly than if they have been 

 previously dried (as is the case with skeletons sent from abroad 

 in a rough state), or if they have been kept in spirit or any other 

 preservative solution. 



When ttie bones are to be removed, the water must be care- 

 fully poured off through a hair seive, and all the solid matter 

 which remains at the bottom of the jar.must be carefully searched 

 from any of the smaller bones which might otherwise be |lost. 



They are then i-emoved to clean water, frequently changed for 

 several days, well washed with a brush if necessary, and dried, 

 if possible, in the sun. 



The process of maceration is necessarily attended with dis- 

 agreeable smells. As long as it continues the surface of the 

 water slowly emits gases ; but the worst is when the water is 

 stirred up by pouring it off to remove the bones. Hence it 

 should be carried on in the open air, or what is far better, in a 

 building isolated for the purpose, and in which the temperature 

 may be kept uniform. When maceration has to be conducted 

 among dwellings, it is necessary to be very careful not to disturb 

 the vessels, and to put some disinfectant, as chloride of lime, 

 into them the day before the contents are taken out. This will 

 obviate most of the usual disagreeable effects, and if not used in 

 too great a quantity, will not cause any material damage to the 

 bones. But chloride of lime, when used too freely, is a dangerous 

 agent ; it destroys the gelatinous portion of the osseous tissue 

 (which of course is not removed in maceration) and leaves the 

 bones white, chalky, and friable. After proper maceration no 

 chemical bleaching is required. Exposure to sunlight or alter- 

 nate sun and rain for some months is generally good, especially 

 for large solid bones, though this may be carried too far, as the 

 intensely white, cracked, porous and fragile condition of osseous 

 fragments which have been lying long on moors or hill-sides, 

 shows. Bones are not naturally of a pure white colour, but 

 have a delicate yellowish or creamy tint like that of ivory. 



Several substitutes for the process of maceration in water are 

 occasionally adopted under special circumstances. 



1. Boiling. This process has the advantage of rapidity, but 

 is seldom resorted to except when absolutely necessary (as in the 

 case of the celebrated skeleton of the '* Irish giant " in the Hun- 

 terian Museum), as the fatty matter in the medullary cavity is 

 melted and pervades the whole osseous tissue, and generally 

 leaves the bones discoloured and greasy, as may be seen in most 

 of those that have been cooked for the table. 



2. Burying in the ground may be resorted to when there are 

 no conveniences for maceration, but it is even a slower process. 

 The effect upon the bones is the same, but they are nearly always 

 stained brown by the colouring matter in the soil, and the small 

 ones are apt to get lost. 



3. It has lately occurred to me, following out a suggestion ot 

 Mr. Seymour Haden'sin his excellent letters, entitled " Earth to 

 Earth," relating to the best, mode of disposing of the dead, to 

 clean bones by burying them in a basket of charcoal, and though 

 the experiments are not quite complete, they promise excellent 

 results, especially as all the disagreeable odour of maceration is 

 entirely obviatetl, and the process may even be carried on in 

 inhabited rooms without any inconvenience. 



{To be continued.) 



OUR ASTRONOMICAL COLUMN 

 A New Star in Cygnus. — On November 24, at Sh. 41m. 

 P.M., the director of the Observatory at Athens, Prof. Schmidt, 

 remarked a star of the third magnitude not far from p Cygni, 

 which was not visible on November 20, the last clear evening 

 previous. Its position from observations with the refractor was 

 found to be in R.A. 2ih. 36m. So"5s., N.P.D. 47° 40' 34" for 

 the beginning of the present year. At midnight its light was 

 more intense than that of t) Pegasi, which is rated a third mag- 

 nitude by Argelander, and very yellow. 



Direct intimation of this discovery was given by Prot. Schmidt 

 to M. Leverrier, and the Paris Bulletin International of De- 

 cember 6 contains the few particulars concerning this star which 

 the generally unfavourable weather up to that date had permitted 

 to be put upon record. M. Paul Henry estimated it of the fifth 

 magnitude, so that as in the cases of the similar suddenly- visible 

 stars of 1848 and 1866, it would appear to have remained but a 

 very short time at a maximum. He considered the colour " green- 

 ish, almost blue" by comparison with Lalande 42,304, not far 

 distant. M. Cornu examined it on December 2 with a spec- 

 troscope applied to the great equatorial, though only during 

 a short break ; the spectrum was chiefly formed of bright 

 lines, and consequently proceeded probably from a vapour or 

 incandescent gas. On the same evening, but under conditions 

 equally unfavourable, M. Cazin made similar observations with 

 a spectroscope on the 9-inch Foucault equatorial, and with the 



